Silver spray paint?

Paint would probably work for a lot of stuff, but it's too late for this year.

Why don't you go shopping in the next few days (brick and mortar or online) to get great post-holiday deals on decor that will look great with your colors? I assume you'll be living with those colors for years to come, and the investment will work out.

Another solution is to put away a lot of your everyday decorative items and replace with holiday cheer. Or just live with the clashing colors; it's the holiday spirit!

I'm late to the party, but you can also add embellishments in your room colors to the decorations -- fabric scraps, ribbon, fibers, etc. -- that will pull them together and make them look purposeful instead of random. And yes, you could also paint them: either spray-paint them metallic (I think copper paint would be beautiful with your decor) or with acrylic/enamel. If you're going to repaint them to keep the design/style, use deeper, richer reds and greens, like cranberry and pine, or lighter ones, like dusty rose and a cactusy-green.

Too late now but the folks at "Live Well" network did spray painting of Christmas decorations & they were beautiful. Think the show was couple of years old but it made things looks so expensive & just beautiful So On Internet google Live Well Network & go to Christmas decorations.

seems like some were kind of coppery-rust & loved them, need to go back & see how they did it. Would be beautiful with South-West décor.